pinctrl: armada-37xx: Add gpio support

GPIO management is pretty simple and is part of the same IP than the pin
controller for the Armada 37xx SoCs.  This patch adds the GPIO support to
the pinctrl-armada-37xx.c file, it also allows sharing common functions
between the gpio and the pinctrl drivers.

Ported to U-Boot based on the Linux version by Stefan Roese.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Konstantin Porotchkin <kostap@marvell.com>
Cc: Nadav Haklai <nadavh@marvell.com>

drivers/pinctrl/mvebu/pinctrl-armada-37xx.c

@@ -20,17 +20,22 @@
 #include <common.h>
 #include <config.h>
 #include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
 #include <dm/pinctrl.h>
 #include <dm/root.h>
 #include <errno.h>
 #include <fdtdec.h>
 #include <regmap.h>
+#include <asm/gpio.h>
 #include <asm/system.h>
 #include <asm/io.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
 #define OUTPUT_EN	0x0
+#define INPUT_VAL	0x10
+#define OUTPUT_VAL	0x18
 #define OUTPUT_CTL	0x20
 #define SELECTION	0x30
 
@@ -189,6 +194,16 @@ const struct armada_37xx_pin_data armada_37xx_pin_sb = {
 	.ngroups = ARRAY_SIZE(armada_37xx_sb_groups),
 };
 
+static inline void armada_37xx_update_reg(unsigned int *reg,
+					  unsigned int offset)
+{
+	/* We never have more than 2 registers */
+	if (offset >= GPIO_PER_REG) {
+		offset -= GPIO_PER_REG;
+		*reg += sizeof(u32);
+	}
+}
+
 static int armada_37xx_get_func_reg(struct armada_37xx_pin_group *grp,
 				    const char *func)
 {
@@ -399,6 +414,149 @@ static int armada_37xx_fill_func(struct armada_37xx_pinctrl *info)
 	return 0;
 }
 
+static int armada_37xx_gpio_get(struct udevice *dev, unsigned int offset)
+{
+	struct armada_37xx_pinctrl *info = dev_get_priv(dev->parent);
+	unsigned int reg = INPUT_VAL;
+	unsigned int val, mask;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+
+	val = readl(info->base + reg);
+
+	return (val & mask) != 0;
+}
+
+static int armada_37xx_gpio_set(struct udevice *dev, unsigned int offset,
+				int value)
+{
+	struct armada_37xx_pinctrl *info = dev_get_priv(dev->parent);
+	unsigned int reg = OUTPUT_VAL;
+	unsigned int mask, val;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+	val = value ? mask : 0;
+
+	clrsetbits_le32(info->base + reg, mask, val);
+
+	return 0;
+}
+
+static int armada_37xx_gpio_get_direction(struct udevice *dev,
+					  unsigned int offset)
+{
+	struct armada_37xx_pinctrl *info = dev_get_priv(dev->parent);
+	unsigned int reg = OUTPUT_EN;
+	unsigned int val, mask;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+	val = readl(info->base + reg);
+
+	if (val & mask)
+		return GPIOF_OUTPUT;
+	else
+		return GPIOF_INPUT;
+}
+
+static int armada_37xx_gpio_direction_input(struct udevice *dev,
+					    unsigned int offset)
+{
+	struct armada_37xx_pinctrl *info = dev_get_priv(dev->parent);
+	unsigned int reg = OUTPUT_EN;
+	unsigned int mask;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+
+	clrbits_le32(info->base + reg, mask);
+
+	return 0;
+}
+
+static int armada_37xx_gpio_direction_output(struct udevice *dev,
+					     unsigned int offset, int value)
+{
+	struct armada_37xx_pinctrl *info = dev_get_priv(dev->parent);
+	unsigned int reg = OUTPUT_EN;
+	unsigned int mask;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+
+	setbits_le32(info->base + reg, mask);
+
+	/* And set the requested value */
+	return armada_37xx_gpio_set(dev, offset, value);
+}
+
+static int armada_37xx_gpio_probe(struct udevice *dev)
+{
+	struct armada_37xx_pinctrl *info = dev_get_priv(dev->parent);
+	struct gpio_dev_priv *uc_priv;
+
+	uc_priv = dev_get_uclass_priv(dev);
+	uc_priv->bank_name = info->data->name;
+	uc_priv->gpio_count = info->data->nr_pins;
+
+	return 0;
+}
+
+static const struct dm_gpio_ops armada_37xx_gpio_ops = {
+	.set_value = armada_37xx_gpio_set,
+	.get_value = armada_37xx_gpio_get,
+	.get_function = armada_37xx_gpio_get_direction,
+	.direction_input = armada_37xx_gpio_direction_input,
+	.direction_output = armada_37xx_gpio_direction_output,
+};
+
+static struct driver armada_37xx_gpio_driver = {
+	.name	= "armada-37xx-gpio",
+	.id	= UCLASS_GPIO,
+	.probe	= armada_37xx_gpio_probe,
+	.ops	= &armada_37xx_gpio_ops,
+};
+
+static int armada_37xx_gpiochip_register(struct udevice *parent,
+					 struct armada_37xx_pinctrl *info)
+{
+	const void *blob = gd->fdt_blob;
+	int node = dev_of_offset(parent);
+	struct uclass_driver *drv;
+	struct udevice *dev;
+	int ret = -ENODEV;
+	int subnode;
+	char *name;
+
+	/* Lookup GPIO driver */
+	drv = lists_uclass_lookup(UCLASS_GPIO);
+	if (!drv) {
+		puts("Cannot find GPIO driver\n");
+		return -ENOENT;
+	}
+
+	fdt_for_each_subnode(subnode, blob, node) {
+		if (!fdtdec_get_bool(blob, subnode, "gpio-controller")) {
+			ret = 0;
+			break;
+		}
+	};
+	if (ret)
+		return ret;
+
+	name = calloc(1, 32);
+	sprintf(name, "armada-37xx-gpio");
+
+	/* Create child device UCLASS_GPIO and bind it */
+	device_bind(parent, &armada_37xx_gpio_driver, name, NULL, subnode,
+		    &dev);
+	dev_set_of_offset(dev, subnode);
+
+	return 0;
+}
+
 const struct pinctrl_ops armada_37xx_pinctrl_ops  = {
 	.get_groups_count = armada_37xx_pmx_get_groups_count,
 	.get_group_name = armada_37xx_pmx_get_group_name,
@@ -444,6 +602,10 @@ int armada_37xx_pinctrl_probe(struct udevice *dev)
 	if (ret)
 		return ret;
 
+	ret = armada_37xx_gpiochip_register(dev, info);
+	if (ret)
+		return ret;
+
 	return 0;
 }